In a railway freight car truck, two axles are held in a pair of laterally spaced sideframes, with a bolster extending laterally between and supported on each sideframe. The wheels are press fit on the axles, with the ends of the axles also fitted with a roller bearing assembly. The roller bearing assembly itself is fit into a bearing adapter that is fit into a pedestal jaw opening at the longitudinal end of each sideframe. The ends of the bolsters are themselves supported on spring groups, which are supported on the lower portion of the center openings of the sideframes.
U.S. Pat. No. 5,562,045 discloses a adapter and pad assembly useful in the fitting of the bearing assembly into the pedestal jaw opening of each sideframe. The bearing adapter, which is itself fit on top of the bearing assembly, is comprised of a unitary cast steel piece. This piece includes shoulders that are laterally spaced to form a receiving opening at each longitudinal edge of the bearing adapter. An elastomeric adapter pad is fitted on top of the bearing adapter. The adapter pad itself is disclosed to be comprised of an injection molded polymer or a castable polyurethane. The adapter pad itself includes depending legs which extend from opposite longitudinal edges of the adapter pad. The depending legs are spaced laterally at each longitudinal edge of the adapter pad such that the depending legs are received in openings between the laterally spaced shoulders of the bearing adapter. One problem with this assembly is the tendency of the adapter pad to move longitudinally across the top of the bearing adapter. This movement is exacerbated by the slight steering movement of the wheel axles in the pedestal jaw openings, such that the movement of the adapter pad completely off the bearing adapter occurs. This is an undesirable situation leading to poor performance of the railway freight car truck. It is also desirable to be able to readily determine the wear condition of the adapter pad.
Accordingly, it is an object of the present invention to provide an improved bearing adapter and pad assembly having a wear member.